1. Technical Field
The present invention concerns a method for manufacturing a particularly resistant film, based on a polymer selected in the group consisting of collagen and glycosaminoglycans, intended to be implanted in the human body, for example for a use as a barrier for the prevention of post-surgical adhesions, in implants such as wall reinforcements in the treatment of hernia.
2. Description of Related Art
Abdominal wall reinforcements are often based on a biocompatible textile support, which is generally porous in order to promote the cell colonization.
Textile supports are intrinsically adhesiogenic and fibrogenic, irrespective of the nature of the tissues with which they are put in contact. This property expressed with respect to the support tissues (muscles, aponeuroses, fascias, etc.) constitutes an indispensable prerequisite for the quality of the result. In contrast, with respect to other more fragile structures, the presence of a textile support during the initial cicatricial inflammation promotes the establishment of dense fibrous links, where only loose links existed, such as those that the interstitial conjunctive tissues procure for the extra-peritoneal organs, and where no link was present for the intra-peritoneal organs. Hence, the porous nature of the textile supports is often the cause of the development of post-surgical erosions and adhesions.
Post-surgical adhesions comprise all non-anatomical fibrous links, fortuitously induced by a surgical act during the normal process of healing. They can cause syndromes which can be mainly classified into chronic pain, occlusive syndromes and female infertility. Moreover, they substantially increase the risks of wrong track during a reoperation, while extending surgery duration, since the prior dissection may be in such cases very tedious.
To remedy this problem, it was suggested to render at least one face of these reinforcement prostheses completely smooth during the initial inflammatory phase, and therefore not favorable to the generation of adhesions. To do this, a physical barrier is interposed between the structures which are not intended to adhere to each other.
WO99/06080 describes a porous textile support intended for a use in parietal surgery, for the repair of eventrations or hernias, a face of which is superficially covered by a smooth resorbable film, the other face being left free for an intimate and early tissue integration. The film of WO99/06080 is obtained via gelling of a starting solution comprising collagen.
Nevertheless, it was found that the films of the prior art used as a barrier for the prevention of post-surgical adhesions may lack mechanical strength and resistance, and may tear up.
Moreover, in the surgical field, it is also possible to use films, which may be transparent, in order to reinforce a portion of an implant where it is desired to practice sutures to secure this implant in the patient's body.
There remains thus a need for a film, preferably smooth, intended to be implanted in the human body, usable as a barrier for the prevention of post-surgical adhesions in an implant, such as abdominal wall reinforcement prostheses, or as a reinforcing element of an area of sutures, having a good elasticity and a good mechanical strength, in particular good tensile strength.